Taking a train is an inexpensive way to get from Milan Bergamo airport to Milan. There is no train station at the airport, so you will need to take a bus to Bergamo and then a train from there.
When your flight lands, you can take ATB bus 1 from the airport into the city. The bus departs from outside of the arrivals hall. When you reach the city, get off at Piazza Marconi, which is where Bergamo train station is located.
From the station, you can take the train to Milan Centrale or Porta Garibaldi train station, both of which are located in the city center.
Trains leave Bergamo for Milan twice an hour at peak times. The journey takes between 48 minutes and 1 hour and 6 minutes, depending on which station you get off at.
One-way tickets to Milan Centrale cost 5.25 euros in second class and 7.90 euros in first class. One-way tickets to Porta Garibaldi cost 4.55 euros in second class (there is no first class service on these trains). Once you get off, you can change to the metro, a bus, or a taxi to get to your final destination.
If you decide not to take a train, other ways to get from Milan Bergamo airport to Milan include taking a bus or rental car.